A basket rescue stretcher of the type utilized by emergency personnel is well known. It generally comprises a sturdy, light-weight, open frame manufactured from stainless steel tubing or like material, comprising both longitudinal and lateral components which are secured by welding or the like, into an integral unit. Common to most rescue stretchers of this type is a sturdy peripheral top rail surrounding the basket stretcher opening, which lends rigidity and strength to the stretcher and also provides a convenient hand-hold for emergency personnel when transporting and injured patient.
Conventional basket rescue stretchers are manufactured from stainless steel components, which are welded together. They generally have a sturdy peripheral top rail of 1-inch diameter, which surrounds the basket stretcher opening and one or more intermediate rails of ½ inch diameter material, spaced from and generally parallel to the top rail. Lateral components, or ribs, are secured by welding to the underside of top rail and to the outside of the intermediate rails. The first intermediate rail is generally spaced 2 inches clear of the top rail.
The top rail is generally the most convenient attachment point for a tether such as ropes or webbing or the like, which enable emergency personnel to either raise or lower the basket rescue stretcher adjacent to a building or an escarpment. Such tethers are commonly secured to the top rail by screwgate carabiners, which are inserted through a pre-formed loop made in the tether and clipped over the peripheral top rail. The tether may be a so-called litter bridle or sling arrangement which may include four equal length ropes or webbing belts connected to a single lifting ring.
Such carabiners are sturdy connection devices, ideally suited to quick connection and release situations. They have a smoothly contoured ‘D’ shape that will only minimally abrade ropes or harnesses. Carabiners may often have corner radii which are smaller than the radius of the tubular top rail. For example a typical top rail may have a radius of ½ to ⅝ of an inch (1 to 1¼ inch diameter) whereas a carabiner may often have a corner radius which is significantly smaller. Thus, the difference in top rail and carabiner diameters prevents the carabiner from properly contacting the underside of the top rail of the basket stretcher as tension is applied. In situations where a “shock load” is placed on the basket stretcher, such as if a loaded stretcher was dropped a short distance and then arrested by the carabiners and connecting tethers, opposite sides of the tubular top rail could be crushed slightly, thereby weakening the rail and perhaps rendering the stretcher unsafe for use.
When the carabiner is clipped over the peripheral top rail of a basket rescue stretcher and tension applied to the connecting tethers, the carabiner will slide along the top rail unless the direction of the tension is close to a right angle with the top rail, or movement of the carabiner is arrested by contact with one of the lateral frame components secured to the top rail. Such movement of the connecting point between tether and stretcher in undesirable since it results in an imbalance of both stretcher and patient and could further endanger the patient.
Further, as tension is applied to the tether straps during suspension of the basket stretcher, the top rail of the basket stretcher prohibits the carabiner from rotating so as to lie in the plane of the tether straps or webbing were the webbing to remain flat, resulting in the carabiner being misaligned generally 90 degrees from such an orientation causing a helical twist in the straps or webbing.
Clipping the carabiner over the top rail of the basket stretcher places a portion of the carabiner in an exposed position outside the periphery of the stretcher. Such an outwardly exposed portion may snag on surface irregularities on the adjacent surface of a building or an escarpment as the basket stretcher is raised or lowered resulting in tipping and jerking of the basket stretcher as it elevates or descends. Further, such contact may result in rapid abrading and deterioration of the carabiner.